For example, sensors comprising such parts are used for the measurement in combustion chambers, for example in glow plugs.
From WO 2006/089446, a part of the type described above is known. It is particularly suitable for the use in glow plugs. However, said part has to be provided with insulated wires to the electrodes, or the insulation thereof with respect to each other has to be achieved with a complex part which engages with said part. These measures are very expensive.
WO 2007/096205 describes a glow plug which for example may use a part of the type described in WO 2006/089446. It comprises a centering element with a centering portion which has to center the part in the glow plug. In order to accomplish the centering, however, the difficulty is to manufacture said centering portion and the surface to which the part adjoins in the required levelness.